Feathered Friends Hummingbird YF 30°F vs Sea to Summit Spark Pro Down Sleeping Bag
Weight and specs compared for 2026 — and which one to choose.
Ultralight 950-fill down bag rated to 30°F (-1°C).
Full details →Ultralight down sleeping bag at 765g with 900+ fillpower RDS-certified down, 15°F rating and Free-Flow Zip system for versatility.
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Feathered Friends Hummingbird YF 30°F vs Sea to Summit Spark Pro Down Sleeping Bag: which should you buy?
If saving weight is your priority, the Feathered Friends Hummingbird YF 30°F wins — at 510 g it is 255 g (33%) lighter than the Sea to Summit Spark Pro Down Sleeping Bag (765 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.
See where both rank against everything else in this category on the lightest sleep system page, or browse the full gear weight database.